Chemical Sciences Journal

Efficient Removal of Cr(VI) from Aqueous Solution onto Palm Trunk Charcoal: Kinetic and Equilibrium Studies

Abstract

Sunil Kumar Yadav and Dixit AK

In the present study, carbonization method using mineral acids at elevated temperature. The potential of chemically carbonized palm trunk charcoal (PTC) for the effective removal of Cr(VI) ions from aqueous solution has been investigated in batch experiments. The sorption kinetics at pH=1.5 and the sorption isotherms at different pHs were studied. Chromium concentration was analyzed spectrophotometrically using 1,5-diphenylcarbazide. In order to the maximal adsorption at pH 1.5 was 24.7 mg g-1. The equilibrium adsorption capacity of PTC increases (4.99 to 24.7 mg g-1) as the initial Cr(VI) concentration increases (10-50 mg L-1). The adsorption behavior of Cr(VI) is best described by the pseudo-second order model and the calculated equilibrium capacity (15.6 mg g-1) agree with the experimental value (14.75 mg g-1). The equilibrium data were well fitted by the Langmuir isotherm model by revealing the maximum sorption capacity of PTC (24.7 mg g-1). The mechanism of adsorption was also studied using Fourier transform infrared (FTIR) spectroscopy. The bond of Cr(VI) to the functional groups of charcoal seems to be irreversible in the case of dried Cr(VI) saturated charcoals.